Current leno patterns formed with conventional method on cloth or textile, are generally further processes on the sheared edge of the pattern, e.g. sealing the sheared edge with a fine thread, to prevent the fiber from being irregular and shedding. In a CN patent application No. 97112584.8, i.e. No. CN1168937A published on Dec. 31, 1997, a pattern generating method through laser processing had been disclosed, wherein, the designed pattern was primarily input into a computer system. Then the material was dyed with deep color and put beneath a scanning laser beam of laser scanner. Under the control of the computer system, scanning movement of the laser beam on the material was operated according to the pattern input to the computer. The areas on the material after laser illumination were decolorized, and the contrast against the areas without laser illumination appears in comparison, thereby the designed pattern being directly shown on the material. The limitation is, wherein, said material must be dyed with deep color. While white or light cloth or fabric can only be adapted for the invention via deep color dyeing. Hence, it is impossible to generate a pattern directly under the premise of keeping original light color according to that invention. In other words, the scope of work is practically reduced by that invention. Moreover, the process of dye not only complicates the procedure and increases the cost, but also requires that the energy of laser should be controlled exactly during operation. Otherwise, if the energy is too small, the decolorized effect is insignificant. If the energy is too strong, the cloth shall be carbonized. Thereby it difficult to realize the object of generating pattern according to that invention. Due to the utilization of dye, it is even causes not only complicated procedure and operation but also environmental pollution.